Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the cauliflower florets with the sliced red bell pepper. Add the oil, ras el-hanout, harissa paste, salt, and stir to coat. Spread on the prepared baking sheet and roast in the oven for 25-30 minutes.
In the meantime, prepare the couscous. Add the dry couscous to a bowl, and set aside. Pour the 3/4 cup of water into a small saucepan. Add the salt and bring to a boil over medium heat. Once boiling, pour over the couscous. Cover with a plate and let it sit for about 5 minutes. The couscous will soak in the water and cook. After 5 minutes, use a fork to mix it and make it fluffy.
Prepare the dressing: in a small blender, combine the fresh basil, mint, olive oil, lime juice, white vinegar, maple syrup, and salt. Blend on high speed until the herbs are very finely chopped. Set aside.
To make the salad, combine the roasted cauliflower, red bell peppers, couscous, kale, radishes, and carrot in a large mixing bowl. Add the dressing and stir to coat.
Serve immediately or refrigerate for about 1 hour before serving.
The couscous salad will keep for up to 3 days in the refrigerator.